* Binocular diplopia occur only if both eyes are open and go to the occlusion of one eye.
* Monocular diplopia persists in the occlusion of the sound eye. Its causes are:
– Corneal: significant astigmatism, corneal pillowcase, keratoconus
– Iris: iridodialysis traumatic
– Cristallinienne: nuclear cataract.
* The nerve IV (trochlear nerve) innervates the superior oblique (oblique) -> moving downwards and inwards.
* Centre for laterality of verticality and convergence center (conjugated movements) -> supranuclear pathways
* Internuclear Routes: (III-VI); located in the medial longitudinal fasciculus
* Binocular vision: law of Hering (nerve impulses are sent in an amount equal to 2 agonist muscles of the eyes); Law Sherrington (when the agonist muscles contract, the antagonist muscles relax). A special case is convergence.
* If the parallelism of the two eyes disappears, an object set by the macula of an eye will be fixed by a extramaculaire area of the other eye. This is the abnormal retinal match.
* Diplopia is absent in the function paralysis (supranuclear palsy)
* In case of paralytic mydriasis (paralysis III), abolition of the direct RPM seen with conservation of the consensus RPM; by against the consensus RPM to the illumination of the healthy eye is abolished.
* Ptosis providential -> masking diplopia
PARALYSIS OF IV:
– Presents a vertical diplopia and oblique marked in downwards and inwards
– This is a catastrophic diplopia in activities such as reading or descending stairs
– Compensatory head position, tilted the healthy side, lowered chin
* Paralysis VI: causes a convergence of the affected eye and a deficit of abduction;offsetting position of the head turned to one side of the oculomotor palsy.
Character: These are oculomotor paralysis without diplopia
Syndrome Foville: Paralysis of laterality
– Paralysis of verticality + convergence paralysis
– Very evocative pinealoma; (Kernel reached III)
– Eye movements are normal the side of the lesion
– When moving the healthy side, the ipsilateral eye can be worn in supply, not exceeding the median line, while the contralateral eye naturally goes in abduction
– Etiology: multiple sclerosis
* Superior orbital fissure syndrome: association of nerve damage III; IV; VI and V1.
* Syndrome apex: slot syndrome sphenoid + monocular blindness did hue of the optic nerve
* Weber’s syndrome paralysis of III + hemiplegia crossed with facial paralysis
* Disorders of colliculi (glioma) achieved kernel IV
Tumors pontomedullary (acoustic neuroma): Kernel VI
* Carotid Aneurysm suptraclinoïdien paralysis of III
* Intracavernous carotid aneurysm infraclinoïdien: syndrome of the outer wall of the cavernous sinus with involvement of III, V, VI and sometimes IV
Arteriovenous Fistula * -> pulsatile exophthalmos; conjunctival vasodilation by medusa head.
* Diabetes: incomplete paralysis of III
* A third nerve palsy with painful phenomena especially binding an urgent search for a carotid aneurysm